Just FYI: The symbol INIT_TASK_SIZE defines the length of a union (task_union) which holds the kernel stack. But when I define this value to be larger than 8192, the kernel wouldn't boot. So this value is probably hard-coded somewhere else.
BTW, I'm using 2.4.26 Does someone know how to increase the kernel stack size for PPC archs? I really need more stack for my external interrupt b/c sometimes the peripheral generates fast bursts on the external interrupt line, which lead to kernel stack overflow. (SA_INTERRUPT doesn't help because this is a realtime interrupt). Any ideas? TIA, Patrick